A place for me to write about things that bore other people, but that interest me.

2010/11/20

Economics of the telecoms industry

I seem to be in a ranty mood at the moment. Today's rant, however, is not negative - it's an education attempt. In particular, I've dealt with one person too many who doesn't seem to understand how the telecoms industry works in an economic sense, and thus why the price they pay their ISP for a home connection isn't comparable to the price a business pays for "similar" connectivity. On the way, I hope to convince people that different ISPs using the same wholesale suppliers can nonetheless offer radically different levels of service.

Time value of money is a useful tool for making capex and opex comparable. The normal way to use it is to calculate the present value of your opex cashflow; this gives you the amount of money you'd need up front to do everything from capital, without supplying future cash for opex (or alternatively without needing to allow for opex into your pricing scheme).

Cost of money is another tool for making opex and capex comparable; whereas time value of money converts opex to capex, cost of money converts capex to opex, by working out how much interest you could have earned (safely) if you didn't spend the money now.

So, with this in place, how does the telecoms industry stack up economically? Well, firstly, there are three activities a telco engages in:

Building and owning a telecoms network, whether a small office-sized one, or a big nationwide network.

Buying access to other telco's networks.

Selling access to their own network.

Of these, the first is dominated by capex; depending on where you need to dig, and who you ask to do the digging, the cost of digging up the roads so that you can run your cables underneath them runs at anything from £20 per metre for some rural areas where no-one's bothered if your trenches aren't neatly filled in afterwards, to nearly £2,000 per metre for parts of London. In comparison, the remaining costs of running cable are cheap - ducting (so that you can run new cable later, or replace cables that fail) is around £3 per metre, expensive optical fibre is around £0.50 per metre (for 4-core fibre, enough to run two or four connections), while traditional phone cable is a mere £0.14 per metre. Even the coaxial cable used for cable TV and broadband is £0.32 per metre.

Once you've got your cables in the ground, you need to put things on the end of them to make them do good things. Using Hardware.com's prices on Cisco gear, and looking at silly kit (plugging everyone into a Cisco 7600 router, and letting it sort things out), you can get gigabit optical ports at aorund £1,000/port for 40km reach, including the cost of 4x10 gigabit backhaul ports from the router to the rest of your network.

Note that all of this is capex; given that your central switching points (phone exchanges, for example) are usually kilometres away from the average customer, you can see that the cost of setting up your network is almost all in building the cabling out in the first place; high quality fibre everywhere can be done retail for £4,000 per kilometre needed (complete with ducting), while your digging works cost you a huge amount more; even at £20 per metre, you're looking at £20,000 per kilometre. The cost of hardware to drive your link falls into the noise.

So, onto the opex of your network. You'll obviously need people to do things like physically move connections around; but most of your ongoing cost is power consumption. Again, this isn't necessarily huge; Cisco offer routers at 50W per port for 10 gigabit use, or 1.2kWh per day. At current retail prices, you'd be hard pressed to spend more than 50p/day on electricity to run the Cisco router, even allowing for needed air conditioning. Reframing that number differently, assuming that the typical customer needs £10/month of human attention, a 10 gigabit link has opex costs of around £40/month, including the 10 gig to other parts of the country.

When you compare this to the capex costs of building your network, you can quickly see that the basis of the telecoms business is raising huge sums of capital, spending them on building a network, then hoping to make enough money selling access to that network that you can pay off your capex, and spend a while raking in the profits before you have to go round the upgrade loop again; your opex costs are noise compared to the money you've had to spend on capex; assuming your network survives ten years, your opex is going to be under £5,000 per port, while your capex for a typical port is going to be over £25,000. Given normal inputs to a time value of money calculation, you can work out that a network has to survive 20 years without change before your opex becomes significant.

So, how do you make money on this? Answer: you sell connections to people; you start by charging some fixed quantity per user, to cover the bare minimum of opex and ensure that no matter how the customer uses the connection, you don't lose money on opex. Then, you add a charge for usage; there are three basic models:

Pay as you use of a high capacity link.

Pay per unit available capacity.

Percentile-based charging of a high capacity link.

The first is the familiar charge per second for phone calls; in this model, adapted for data connections, I pay you per byte transferred. You set the price per byte as high as you think I'll pay, so that you can pay off your capex, make a profit, and prepare for the next round of capex on network upgrades. You may also offer a variable price for usage (as my ISP, Andrews & Arnold do), in order to encourage users to shift heavy use to times when it doesn't affect your network as much. This is also where peak and off-peak phone charges came from; if you use the phone at a time when the existing network is near capacity, the telco charged you more in order to encourage you to shift as much usage as possible to off-peak, where there was lots of spare capacity, and hence allow the telco to delay upgrades.

The second is also simple. I pay you for a link with a given communications capacity, and I get that capacity whenever I use it; paying for unlimited phone calls is an example, as is an unlimited Internet connection. In this model, the telco is playing a complex game; if they make the price for the capacity too low, people will use enough capacity on the "unlimited" link that you have to bring forwards a high-capex network upgrade. If you set it too high, people will go to your competitors; a median position, used especially by consumer telcos, is to offer "unlimited with fair use", where you will be asked to reduce your usage or disconnect if you use enough that a network upgrade is needed to cope with you. This position can cause a lot of grief; people don't like to be told that, actually, this good deal for their usage level isn't for them, and that they're "excessive" users.

The third option (percentile billing) is the most common option used in telco to telco links. In a percentile billing world, there is a high capacity link that neither end expects to see fully utilised. Instead, the current utilisation is measured repeatedly (e.g. once per second). The highest measurements are ignored, leaving the percentile behind. Payment is then made based on the peak utilization in the percentile. A very common version of this is monthly 95th percentile; as used by ISPs, you measure once every second. You sort your month's measurements, and discard the highest 5% (e.g. in September, a month with 30 days, you have 2,592,000 seconds; you discard your highest 129,600 readings to get your 95th percentile). You then charge for the highest remaining measurement. For a simplified example; imagine that I measured a day's usage, and charged you 75th percentile. In February, you used 5 units a day for the first week, 1 unit a day for the next 20 days, then 50 units on the last day. 75th percentile of 28 periods involves discarding the highest 7 measurements, so I discard the 50, and 4 of the 5s, to get a measurement of 5 units peak use. I thus charge you for 5 units/day for the entire month. Had you been able to keep the last day at 1 unit, your bill would have fallen to just 1 unit/day; you can thus see how percentile billing avoids charging for rare peaks, but doesn't let a user get away with lots of heavy use cheaply.

I hope this has piqued some interest; as you can see, running a telco, especially at consumer prices, is much more akin to running a mortgages bank than a shop.